This invention relates to an improvement in fruit and vegetable juice extractors of the type wherein the fruit and vegetables or the like are grated or ground and centrifuged for separation of the juice from the pulp or solid part.
One of such juice extractor is described in the specification of the U.S. Pat. No. 2,343,327, which discloses:
A fruit and vegetable juice extractor comprising a rotary food basket mounted on a substantially vertical axis of rotation and having an annular concentric perforated side wall and a bottom wall and adapted to receive ground food such as fruits and vegetables and the like adjacent the bottom thereof, means to deliver food to be ground to said bottom wall, means for rotating said basket about its axis at a high velocity of several thousand revolutions per minute to effect a centrifugal movement of the ground food outwardly against the lower part of said wall, the lower part of said wall being formed with a shoulder to receive and break up the ground food centrifugally thrown thereagainst, the remainder of said wall sloping upwardly and outwardly from said shoulder to facilitate the upward travel of the ground food thereover in a relatively thin layer, and juice collector means surrounding said wall and adapted to receive the juice centrifugally expelled through said wall.
In such a conventional juice extractor, the food grated by the cutting teeth on the inner bottom face of the inverted frusto-conical rotatable basket slides on the inner bottom face by the centrifugal force radially to the low vertical shoulder part of the filter net and then upwardly on the frusto-conical filter part. Since the height of the vertical shoulder part is very small compared to the filter part of the wall, the ground mixture of the juice and the pulp are driven smoothly and quickly towards the frusto-conical filter part. Therefore, the mixture of the juice and pulp travels too fast toward the peripheral part of the basket, and hence a considerable amount of the juice flows together with pulp away from the upper periphery of the basket, with the juice not being effectively extracted from the pulp, thereby resulting in a relatively low extraction ratio.
The present invention provides a juice extractor with a frusto-conical centrifugal basket capable of attaining a higher juice extraction ratio. This is achieved by relative dimensioning of the basket's pot wall and the pressing member's bottom and the angle of the wall to reduce the speed with which the pulp passes to and over the filter.